Display devices, such as liquid crystal displays (LCD), often include voltage regulators to supply power to various components within the display. For example, in an LCD, a backlight illuminates the back side of an array of thin-film transistors. Each of the transistors in the thin-film array acts like a tiny shutter that can open or close to pass more or less light from the backlight. The amount of light passed by a transistor is controlled by the amount of voltage applied to it. In a typical display, 64 different levels of voltage may be applied to each transistor. Voltage regulators are usually used to provide these and other voltage levels in a display.
Each transistor may represent one tiny dot on an LCD, and an LCD may include hundreds of thousand, or even millions, of these tiny dots. By individually controlling the amount of light passed by each transistor, an image can be displayed on an LCD.
In order to coordinate so many levels of voltage applied to so many transistors, a great deal of control circuitry is often needed. The control circuitry in a display often consumes a relatively large amount of power in many devices. High power consumption can be undesirable, especially in mobile devices like laptop computers.